It is popularly thought that today's existing hunter-gatherers lived until recently in isolation, independent of food-producing peoples. The present thesis takes a different view, proposing that middle-to-late Holocene foragers followed an economy based heavily on trade relationships with neighboring food producers. It is argued here that the symbiosis observed today among such groups as Southeast Asian Negritos, the !Kung Bushmen, and the African Pygmies is neither recent nor anomalous but reflects a subsistence strategy that has been followed by most hunter-gatherers for millennia.